## noVNC: HTML5 VNC Client
### Description
noVNC is a VNC client implemented using HTML5 technologies,
specifically Canvas and WebSockets (supports 'wss://' encryption).
noVNC is licensed under the
[LGPLv3](http://www.gnu.org/licenses/lgpl.html).
For browsers that do not have builtin WebSockets support, the project
includes [web-socket-js](http://github.com/gimite/web-socket-js),
a WebSockets emulator using Adobe Flash .
Special thanks to [Sentry Data Systems](http://www.sentryds.com) for
sponsoring ongoing development of this project (and for employing me).
Notable commits, announcements and news are posted to
@noVNC
### Screenshots
Running in Chrome before and after connecting:
See more screenshots here.
### Requirements
Unless you are using a VNC server with support for WebSockets
connections (only my [fork of libvncserver](http://github.com/kanaka/libvncserver)
currently), you need to use a WebSockets to TCP socket proxy. There is
a python proxy included ('wsproxy'). One advantage of using the proxy
is that it has builtin support for SSL/TLS encryption (i.e. "wss://").
There a few reasons why a proxy is required:
1. WebSockets is not a pure socket protocol. There is an initial HTTP
like handshake to allow easy hand-off by web servers and allow
some origin policy exchange. Also, each WebSockets frame begins
with 0 ('\x00') and ends with 255 ('\xff').
2. Javascript itself does not have the ability to handle pure byte
arrays. The python proxy encodes the data as base64 so that the
Javascript client can decode the data as an integer array.
### Quick Start
* Use the launch script to start a mini-webserver and the WebSockets
proxy. The `--vnc` option is used to specify the location of
a running VNC server:
`./utils/launch.sh --vnc localhost:5901`
* Point your browser to the cut-and-paste URL that is output by the
launch script. Enter a password if the VNC server has one
configured. Hit the Connect button and enjoy!
### Advanced usage
* To encrypt the traffic using the WebSocket 'wss://' URI scheme you
need to generate a certificate for the proxy to load. By default the
proxy loads a certificate file name `self.pem` but the `--cert=CERT`
option can override the file name. You can generate a self-signed
certificate using openssl. When asked for the common name, use the
hostname of the server where the proxy will be running:
`openssl req -new -x509 -days 365 -nodes -out self.pem -keyout self.pem`
* `tightvnc` provide a nice startup script that can be used to run
a separate X desktop that is served by VNC. To install and run the
server under Ubuntu you would do something like this:
`sudo apt-get install tightvncserver`
`vncserver :1`
The VNC server will run in the background. The port that it runs
on is the display number + 5900 (i.e. 5901 in the case above).
* `x11vnc` can be used to share your current X desktop. Note that if
you run noVNC on the X desktop you are connecting to via VNC you
will get a neat hall of mirrors effect, but the the client and
server will fight over the mouse.
`sudo apt-get install x11vnc`
`x11vnc -forever -display :0`
Without the `-forever` option, x11vnc will exit after the first
disconnect. The `-display` option indicates the exiting X display to
share. The port that it runs on is the display number + 5900 (i.e.
5900 in the case above).
* To run the python proxy directly without using launch script (to
pass additional options for example):
`./utils/wsproxy.py -f source_port target_addr:target_port`
`./utils/wsproxy.py -f 8787 localhost:5901`
* To run the mini python web server without the launch script:
`./utils/web.py PORT`
`./utils/web.py 8080`
* Point your web browser at http://localhost:8080/vnc.html
(or whatever port you used above to run the web server). Specify the
host and port where the proxy is running and the password that the
vnc server is using (if any). Hit the Connect button.
### Browser Support
In the following table Jaunty is Ubuntu 9.04 and WinXP is Windows XP.
#### Linux (Ubuntu 9.04)
OS | Browser | Status | Notes |
---|---|---|---|
Jaunty | Chrome 5.0.375.29 | Excellent | Very fast. Native WebSockets. |
Jaunty | Firefox 3.5 | Good | Large full-color images are somewhat slow from web-socket-js overhead. |
Jaunty | Firefox 3.0.17 | Fair | Works fine but is slow. |
Jaunty | Opera 10.60 | Poor | web-socket-js problems, mouse/keyboard issues. See note 1 |
Jaunty | Arora 0.5 | Good | Broken putImageData so large full-color images are slow. Uses web-socket-js. |
Jaunty | Konqueror 4.2.2 | Broken | web-socket-js never loads |
WinXP | Chrome 5.0.375.99 | Excellent | Very fast. Native WebSockets. |
WinXP | Firefox 3.0.19 | Good | Some overhead from web-socket-js. |
WinXP | Safari 5.0 | Fair | Fast. Native WebSockets. Broken 'wss://' (SSL) - weird client header |
WinXP | IE 6, 7, 8 | Non-starter | No basic Canvas support. Javascript painfully slow. |